Mechanism of film propulsion



Sept 27 17932 c. AscHENBRr-:NNER 1,879,866

ECHNISH 0F FILM PRQPULSION v Filed oct. 4. 1929 Claus /sz/renre/me Y v Patented Sept. 27, 1932 UNITED STATES PATENT OFFICE CLAUS ASCHENERENNER, or MUNICH, GERMANY, ,AssiGNoR 'ro THE FIRM PHOTO- GRAMMETRIE G. M. E. n., or MUNICH, GERMANY MECHANISM'. 0F FILM PROPULSION Application led October 4, 1929, Serial No. 897,205, and in Germanyl October 8,k 1928.

My invention relates to improvements in a mechanism for imparting longitudinal displacement in a photographic film used in cameras adapted to take a series of successive exposures from a fiying machine in motion.

Cameras used in this Work require the most reliable mechanism in order to insure exact longitudinal displacement of the film for each successive exposure and it has been found that the devices now in use are either unreliable as regards the proper measured movement of the film where a friction drive is utilized, or de` structive to the film material Where sprocket wheels engage in perforations in the film to not only impart movement to the latter but to stop its movement as Well.

With the foregoing in mind, it is the purpose of the present invention to provide a mechanism for impartingthe required movement to a film of this character and to bring it to the exact successive stop positions Without in any way impairing the condition of the film. I accomplish this purpose by means of the device hereinafter described in the specification, set forth in the appended claim and illustratively exemplified in the accompanying drawing, which is a perspective view of a casing with one of its side wallsremoved to disclose the enclosed mechanism.

Referring to the drawing in detail, l0 denotes the housing which is a substantially rectangular member having a rectangular opening or slot z' in its bottom Wall, the sides of the slot forming the frame for the picture. Spaced from opposite ends of the slot e7' and journaled in the side Walls of the housing are rollers beach of which has its periphery at one point spaced from the bottom Wall a distance equal to the thickness of the film strip 11 so that the latter passes between the rollers `h directly over the opening z'. At one end of the housing l0 the film strip passes over the roller 71. from a spool or reel g which carries the unexposed film and which turns on its axle in the side Walls of the housing. The other roller L delivers the film to al take-up spool or reel e journaled in the sides of the housing at the end of the latter opposite that occupied by the spool g. A

The mechanism for operating the take-up' spool e comprises a spur gear l mounted on the axle of thespool and' turning with the'latter. The gear l meshes with a small drive gear or pinion c, which is mounted lto turn With adrive shaft b, and which is attached to a toothed ratchet -Wheel p. The shaft ro` tates in bearings in the side Walls of the housing and at one end outside the Wall, it is provided with a crank and handle a. Rotary movement of the crank a in clockwise direction will impart movement to the shaft b and gear or pinion c, which in turn imparts rotary movement in the opposite direction to the take-up spool e through the gear d.

The film according to the present invention is provided along preferably one longitudinal marginal edge with a series of pe-rf'orations Isl, cg, las, ki which are spaced from each other a distance equal to the length of each successive picture to be taken. The mechanism for controlling the exact positioning of the film comprisesa'lever Z` arranged over the perforated margin of the film and pivotally supported in a side ivallof the housing. The shorter end of the lever Z'is'provided With'a downwardly directed projection orstop lug m adapted to ride over the film and drop into each perforation k1 ctc. as hereinafter 'described. The opposite end of the lever has a right angle projection which engages under a flange or disc r of an upright rod g slidably mounted in the bottom and top 'Walls of the housing. The upper end of the rod projects above the top Wall and is' provided with a button, While the portion of the rod between' the disc r andthe inner surfaceof the bottom Wall carries a spring to yieldably urge the rod'- "end, engages the teeth of the piniongear c along the lower portion of its periphery.

The dog s is yieldably held in engagement with the pinion c by means'of a spring t which is attached to the dog at one end and toa point on the lever Z adjacent the end Vunder the disc 1' at the other end. In order to hold the vend ofI the lever in contact With the under side of the. disc 7' andthe projection m in Contact with the margin of the filmA during movement thereof, and in a perforation k1 etc. when the film is not in movement, I provide the portion of the lever between its pivot and the dog s witha spring n which has 'its fixed end at a point above the lever. The

entire movement of the take-up reel e and drive is brought to a halt when the projection m drops into a perforation k1 etc. and the longer end of the lever is raised, by means of a beveled tooth o rojecting from the upper side of the lever an being disposed to engage in a tooth of the ratchet wheel p.

As will be gathered from the foregoing, the i mechanism for advancing the film is quite separate from that contemplated to stop its movement at the desired position, whereby practically no strain is absorbed by the film. Assuming the device is to be set in operation from the position shown in the drawing, the operator depresses the rod g which through the disc 7 causes the longer arm of the lever Z to be lowered andthe shorter arm to be raised,

the latter withdrawing the projection m' this point, the projection m drops into the perforation and stops further movement of the film, but before any strainjhas been exerted on the latter by the projection entering the perforation, the tooth 0 has engaged a tooth of the ratchet rotary movement of t e driving shaft b and reel e. To prevent rotation of the shaft Z2 before the projection m has been completely Withdrawn from the perforation, the dog s is carried towards the left to remain in engagement with the gear until the disengaged per-` foration of the film may advance out of register with the projection. Y

Having now described my invention and the manner invwhich the device operates, what I claim and desire'to secure by Letters Patent 1s:

A device for feeding and controlling per forated photographic film, comprisingy a driven take-upy spool, a d-etent yieldably urged into contact with said ilm and into the path of the perforations thereof, said detent having a toothed edge and a pivotally mounted dog yieldably urged to upright pcf sition, a rotary `drive for said spool, comprising a Gear meshing with the spool and engaged tby the dog in its upright position to hold the detent released from the film, a.

toothed wheel engaged by the toothed edge of the detent to prevent movement of the drive in winding direction, and means to release the detent and toothed wheel and to permit the dog to engage the gear until the disengaged perforation of the film is advanced out ofk register with the detent.

In testimony whereof'I hereunto aiix my signature. Y

CLAUS ASCHENBRENNER.

and arrested further j 

